1. Field of the Invention
The present invention relates generally to itinerary preparing systems, and more particularly to an itinerary preparing system capable of preparing a complete travel plan that efficiently incorporates desired visiting places.
2. Description of the Related Art
Recently, a communication system has been proposed which performs data communication between an information control center and a terminal, such as an on-vehicle terminal installed on a vehicle or a portable terminal which a user can carry anywhere, so as to provide information of an optimum transportation route. Similarly, a communication system capable of providing various services including reservations for amusement facilities or restaurants has been proposed as well. These communication systems can effectively provide the user-required information if the system is combined with a navigation system. The navigation system indicates current and destination positions on a self-contained map, wherein the current position is recognized by a current position detecting sensor, such as a GPS (Global Positioning System) or a direction sensor. Based on the position information, the navigation system provides a recommended transportation route. By using this system, one can travel through an optimum route, while getting various services. Moreover, if desired destinations, date, and time are input to the system in advance, an appropriate itinerary (or transport schedule) can be prepared before departure, thus enhancing enjoyment of a motoring excursion.
Another navigation system which has been proposed so far includes an apparatus capable of searching possible facilities which one can reach within a limited time, and providing the acquired information to the user. For instance, Japanese Patent Laid-Open Publication No. Hei 7-55484 discloses a navigation system which utilizes map data or traffic condition data to suggest how far one can reach or which route is suitable within a prescribed time period entered by the user, or indicates a possible area range based on the remaining fuel amount. According to this navigation system, the reachable area range can be easily known, so that the user can prepare a more detailed itinerary based on the acquired information.
However, the information collected by the aforementioned navigation system is limited to information such as the departure and return time, or reservations for and possibilities of reaching the visiting places (including intermediate locations and destinations). As such, it is difficult to know the timewise relationship between individual pieces of information in the itinerary, and it is difficult for a user to understand an entire overview of an itinerary. For instance, if an itinerary includes only one visiting place and the system assures the possibility of reaching the place, a situation may arise where one cannot complete the trip within the user-intended total time due to a traveler's overstay at the visiting place. In other cases, where the itinerary includes a plurality of visiting places together with time restrictions such as a specific arrival time or length of stay at each visiting place, and therefore the flexibility of the itinerary is decreased, it may not be possible to incorporate all visiting places within the user-intended total time of the trip, or it is likely that the same time slot may be specified as the arrival time at multiple places. Consequently, the itinerary becomes imperfect. When this occurs, the itinerary needs to be revised. However, a problem is that one cannot easily determine what part of the itinerary should be revised. As such, itinerary preparation becomes complicated.
Worse, it is likely that adjustment of the itinerary is incorrect and the visiting place where one wants to visit most may be adjusted inappropriately or inadvertently deleted. As a result, preparation of the itinerary becomes even further complicated and time-consuming.